Rotary actuator assemblies are generally known to those skilled in the art. Rotary actuators are useful in combination with grippers, slides, or other devices that require rotational movement in addition to their function. One type of rotary actuator includes a vane that swings in response to air pressure exerted thereon, to rotate a body. Another type of rotary actuator uses a rack and pinion assembly, wherein an actuator engages the rack, which in turn engages the pinion. Linear motion of the rack causes the pinion to rotate. Moving the rack reciprocally causes similar reciprocal rotation of the pinion. In contrast to the vane-type actuator, the rack and pinion embodiment translates linear motion of the rack into rotational movement of the pinion. It is known in the art, however, that conventional rotary actuator designs tend to be structurally complex and expensive to produce.
It would, therefore, be desirable to provide a rotary actuator assembly of alternate configuration to perform the above-described and other functions typical of rotary actuator assemblies.
Accordingly, an illustrative embodiment of the present invention provides a rotary actuator assembly which comprises an actuator, at least one piston, a longitudinally-extending flexible member, a set and a pinion. The piston is movable in response to the actuator. The flexible, longitudinally-extending member is attached to the piston. The set is attached to the flexible member. The pinion is engagable with the set such that when the flexible member moves, so too does the pinion.
In the above and other illustrative embodiments, the rotary actuator assembly may also provide: the actuator being pneumatic; movement of the pinion being rotational; the flexible member conforming to a portion of the pinion; the flexible member being a cable; a piston being attached to opposed portions of a cable; the set being a bearing; a pinion comprising a cavity to receive a bearing and a pathway to receive at least a portion of a cable; movement of the piston being linear and movement of the pinion being arcuate; movement of the pinion being rotational; a stop being engagable with a pinion to limit its movement; a seal located between a set and a piston; a flexible member being disposed through a seal; a portion of the seal forming a seal between itself and the flexible member when the piston moves in response to an actuator; an adjustable member being selectively movable relative to a pinion and engagable with the same; and an adjustable member being engagable with a stop to prevent backlash on a set and pinion.
Another illustrative embodiment of the present invention provides a rotary actuator assembly which comprises an actuator, a longitudinally-extending, flexible member, and a pinion. The longitudinally-extending, flexible member moves linearly in response to the actuator. The pinion engages the flexible member, wherein linear movement of the flexible member translates into rotational movement of the pinion.
In the above and other illustrative embodiments, the rotary actuator assembly may also provide: a flexible member comprising a fastener attached thereto which engages a pinion to cause the pinion to pivot; an actuator being pneumatic; a piston being attached to opposed portions of a flexible member; a fastener being a bearing; a pinion comprising a cavity to receive the bearing and a pathway to receive at least a portion of a flexible member; a stop engagable with the pinion to limit movement of the same; a seal located between a fastener and a piston; a flexible member being disposed through a seal; a portion of a seal forming a seal between itself and the flexible member when a piston moves in response to an actuator; an adjustable member that is selectively movable relative to the pinion and engagable with same; and an adjustable member being engagable with a stop to prevent backlash on a bearing and the pinion.
Another illustrative embodiment of the present invention provides a rotary actuator assembly which comprises a housing, a pinion, a cable, a first piston and a second piston. The pinion is located in the housing, wherein the pinion is rotatable relative to the same. At least a portion of the cable is disposed in the housing and is circumferentially engagable with the pinion. The first piston is engagable with one end of the cable, and the second piston engagable with another end of the cable. The first and second pistons are movable linearly to cause the pinion to rotate.
In the above and other illustrative embodiments, the rotary actuator assembly may also provide: first and second pistons being disposed in first and second chambers, respectively, and wherein fluid is deposited in the first and second chambers to move the first and second pistons linearly; pistons moving linearly in alternate directions within the chambers; at least a portion of the cable being attached to the pinion so alternate linear movement of the pistons translates into alternate rotational movement of the pinion; a cable wraps around a portion of the pinion; and a fastener attaches a cable to the pinion.
Another illustrative embodiment of the present invention provides a rotary actuator assembly which comprises a selectively rotatable body, a flexible, longitudinally-extending means and an actuation means. The flexible, longitudinally-extending means engages and selectively rotates the rotatable body. The actuation means moves the flexible longitudinal extending means to rotate the rotatable body.
Additional features and advantages of the rotary actuator assembly will become apparent to those skilled in the art upon consideration of the following detailed description of the illustrated embodiment exemplifying the best mode of carrying out the rotary actuator assembly as presently perceived.
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates various embodiments of the rotary actuator assembly, and such exemplification is not to be construed as limiting the scope of the rotary actuator assembly in any manner.